John thompson



Patented May 11, 1886.

UNITED STATES PATENT Orricn.

JOHN THOMPSON, OF BUOYRUS, OHIO, ASSIGNOR TO THE BUGYRUS FOUN- DRY AND MANUFACTURING COMPANY, OF SAME PLACE.

DREDGlNG-MACHINE.

SPECIFICATION forming part of Letters Patent No. 341,613, dated May 11. 1886.

Application filed October 27, 1885. Serial No. 181,095. (No model.)

.To all whom it may concern: load-sustaining mechanism proper, allof which Beitknown that I, JOHN THOMPSON, a citirotate with the load.

zen of the United States, and a resident of F F is a circular frame or wheel, which is 55 Bucyrus, in the county of Crawford and State preferably centered at the head of the mast.

5 of Ohio, have invented certain new and use- It is rigidly attached to the stringpieecs E ful Improvements in Dredging-Machines, of of the frame E E, and is preferably made, as which the following is a specification. shown, in the form of a complete wheel Myinvention relates to improvements in the grooved on its edge, within which groove the 60 mechanism employed forswinging the boom or chain which swings the frame E E and the i loadcarryiug arm in the class of machines in boom and its load will be held.

which dredges, derricks, steam-shovels, and Instead, however, of the continuous or comthe like are embraced; and, more specifically plete wheel F,segments of a wheel fastened to stated,it consists, first, in a combination of do, the frame E E may be used; or a part of the 6 vices, whereby the power which swings and frame or a beam fastened crosswise thereon controls the load during its swinging action may be used, provided it extends laterally a may be increased, thereby securing more safe sufficient distance to give the requisite leverand absolute command over theload, and, secage for the pull of the chains, they being atond, in the introduction of elastic or yielding tached to the ends thereof on each-side of the 70 mechanism between the power and the load, frame E E. I prefer the wheel. or segments whereby the shock or strain on the machine thereof, however, because by their use the consequent on rapid action thereof, especially chain, being free to leave the groove as the with heavy loads, will be taken up or absorbed, mechanism revolves,will always pull on a tanthus also inducing safety and reducing liabilgent from the periphery, thus always inaiu- 7 5 ity of fracture of the mechanism. taining a leverage equal to the radius of the 2 5 In the drawings the same referencelet-ters wheel or segments thereof.

indicate like parts in all the figures. They G G are chains, which, by preference, are represent my invention as appied to a dredgthe ends of a continuous chain which passes ing-machine; but,as above stated,it is equally around the wheel F and takes firm hold on it, s applicable to other machines inwhich a roeither'by reason of its friction against the ,0 tatable load-supporting boom, arm, or table same, which will be found sufficient in most is to be moved or turned. cases; or, if there shall not be sufficient fric- Figure 1 illustrates a side elevation of a tion to prevent slipping, then I employ teeth dredge embodying my invention. Fig. 2illusor like devices upon its periphery, which en- 8 trates a top plan view of the same. Fig. 3 gage with the links of the chain, and which illustrates a detailed view of one method of will make the wheel practically a sprocketconstructing the elastic mechanism to prevent wheel, so called. The chain may, however, fracture of the parts consequent on jerk, &c. be made in two separate lengths, the ends A is the scow or float. B is a frame erected whereof are attached at suitable points on the 0 thereon for the supportof certain parts of the Wheel'F, or on the laterally-extending parts 40 mechanism. of the frame E,if such extensions be used in- G is the mast, which may be rigidly atstead of the wheel. tached to the frame and to the scow, the ro- H H and H H are idlers, which properly tatable upper parts turuiiig upon it as a cenguide the chains G G,ifsuch guiding is desir- 95 ter, or it may itself be rigidly attached to the able, and I I are two sheaves attached to the rotating parts and swivel on or in suitable supfree ends of these chains.

porting devices, all as usual in such struct- J J are two additional chains, which pass ures. through the sheaves I I, respectively. Their D is a boom,suitably supported at its lower ends (shown at K K) are attached to the frame 100 end, (7, and carrying its load at the other end, B at any suitable point, or to any othersuitable (1, also as usual. support. These connections may be rigid ones, E E represent the swinging frame and its if preferred; but in order to reduce the strain stay-rods, &c., for supporting and guiding the consequent on starting or stopping the swing of a heavy load I prefer to attach these ends of the chains J J by means of an elastic conneetion of any suitable construction, and which may consist of a hook or an eyebolt, L L, which slides through a plate, M, which is rigidly attached to the frame B or other suitable support, the. end of the shank of the hook or bolt being provided with a washer and nut or head, N, a stiff spring, 0, being interposed be tween the plate M and the washer N. These devices are best seen in Fig. 8. The other ends of the chains J J, respectively, are at tached to opposite sides of the drum P, which is turned by any suitable mechanism connecting with the engine or other source of power, as usual. Thus upon rotating the drum one of the chains will be wound up and the other un' wound, the action being reversed when the drum is reversed.

If desired, the chains G G may be attached to the wheel F by elastic connections, as above described, to increase the elasticity of these parts; or the sheaves I I may be attached to the chains G G by like connections. Such additional yielding connections may be used in addition to the connections at the fast ends of the chains J J, and this feature may be employed when single chains extend directly from the wheel F or its equivalent to the drum B withoutthe employment of the doubled chains J J; but I prefer the latter, because by their use the power is greatly increased, thus giving greater control over theload and greater safety in its movement.

If the elastic connections are applied to the chains G G, care must be taken that they are so placed on the wheel F or its equivalent, as above described, that the binding of the chain against them will not by the friction engendered interfere with the free action of the elastic connections.

It will be readily understood that ropes may be used instead of the chains G and J, and also that sections of rods may be employed instead of continuous chains or ropes as part thereof.

The operation of the several devices is obvious. The load,bci 11g suitably elevated,is swung O are so stiff that during this pulling action they yield only sufficient to ease the starting of the rotatable mechanism and the load. Vhen, however, the load has been swung as far as desired, the drum 1? may be stopped at once and the lowering action commenced, the strain or jerk occasioned thereby being taken up by the elasticity or yielding of the springs O 0. Moreover, when the double chainsJ J are employed, the power will be so increased that the drum may be started rapidly and run rapidly, thus resulting in gain in speed during the swinging action, notwithstanding the fact that a greater amount of chain has to be wound up and unwoun'd,because of the doubling thereof, and the load being so perfectly under control and prevented from exerting its weight injuriously, risk of fracture of the mechanism,

and consequent accident to the workmen, is avoided.

I do not limit myself to the details of construction shown and described, since it will be obvious to those who are familiar with this art that they may besomewhat departed from and yet my invention be employed.

Having described my invention, I claim- 1. The combination, in a dredge or other like machine, of a rotatable boom, arm, or table provided with draft-chains attached thereto on opposite sides, sheaves on the ends of the chains, doubled chains passing through the sheaves, respectively, the ends whereof are attached to suitably-located elastic fastening devices, the other ends whereof, respectively, are attached to a rotatable drum, and mechanism for rotating the drum, substantially as and for the purposes set forth.

2. The combination, in adredge or like ma chine, of a rotatable boom, arm, or table having draft-chains attached thereto on opposite sides, the free ends whcreofare provided with sheaves, doubled chains running through the sheaves, respectively, the ends whereof are attached rigidly to the frame and to a rotatable drum, and suitable mechanism for rotating the drum, substantially as and for the purposes set forth.

Signed at New York, in the county of New York and State of New York, this 23d day of October, A. D. 1885.

JOHN THOMPSON.

'Wi tn essesi JOHN H. has, JOHN J. OAULDWELL. 

